<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Hi Luke, <div> </div><div>The power requirements depend on how you wish to use your HPSDR system. </div><div><br></div><div>Below is a message from Phil on the issue that may be helpful to you. It was posted to the reflector on Nov 9, 2011. The latest Mercury firmware also contains the power managment code mentioned in the message: </div><div><br></div><div><blockquote type="cite">***** High Performance Software Defined Radio Discussion List *****<br><br><div><font face="Arial">All,</font></div><div><font face="Arial"></font> </div><div><font face="Arial">We have completed the process of merging Joe's, K5SO, FPGA code and the previous releases.</font></div><div><font face="Arial"></font> </div><div><font face="Arial">In which case there are new versions of code available as follows:</font></div><div><font face="Arial"></font> </div><div><font face="Arial">Mercury_V3.1</font></div><div><font face="Arial">Penelope_V1.6</font></div><div><font face="Arial">Metis_V1.6</font></div><div><font face="Arial">Ozy_Janus_V2.1</font></div><div><font face="Arial"></font> </div><div><font face="Arial">The code will be available from the Wiki download page shortly and the source is in SVN. For those using Ozy to load new code, updated programmer batch files are available from SVN under ...\USBBlaster-Binaries.</font></div><div><font face="Arial"></font> </div><div><font face="Arial">In order to use this new release of code you must upgrade ALL your boards to the latest revision.</font></div><div><font face="Arial"></font> </div><div><font face="Arial">The new code enables up to four receivers to run on one Mercury board or up to four individual Mercury boards to be fitted to the Atlas bus.</font></div><div><font face="Arial"></font> </div><div><font face="Arial">Please note that when enabling additional receivers on the one Mercury board then the current drawn from the +5v rail will increase as follows:</font></div><div><font face="Arial"></font> </div><div><font face="Arial">For a system comprising Metis, one Mercury, Excalibur and Penelope the current draw from the +5v rail is:-</font></div><div><font face="Arial"></font> </div><div><font face="Arial"> One receiver running = 1.53A<br> Two receivers running = 1.71A<br> Three receivers running = 1.90A<br> Four receivers running = 2.02A</font></div><div><font face="Arial"></font> </div><div><font face="Arial">For a system comprising Metis, Excalibur and Penelope the current draw from the +5v rails with :</font></div><div><font face="Arial"></font> </div><div><font face="Arial"> One Mercury board = 1.53A</font></div><div><font face="Arial"> Two Mercury boards = 2.4A</font></div><div><font face="Arial"> Three Mercury boards = 3.08A</font></div><div><font face="Arial"> Four Mercury boards = 3.51A</font></div><div><font face="Arial"></font> </div><div><font face="Arial"></font> </div><div><font face="Arial">Note that the LPU may not have sufficiant capacity to support additional receivers. Joe has been able to switch the clocks off inside the FPGA to Mercury receivers that are not being used. In this way the current draw only increases as you add additional receivers. However, once you have selected more than one receiver you can't selected a lesser number without first selecting the new number of boards and then cycling the power to the Atlas board.</font></div><div><font face="Arial"></font> </div><div><font face="Arial">With respect to how Alex operates when using multiple Mercury receivers or boards here is what happens:</font></div><div><font face="Arial"></font> </div><div><font face="Arial">1) When using a single receiver Alex switching is done normally. That is, filter switching is done automatically at the <br>frequency break points currently coded unless "manual Alex control" is selected via the PC in which case the <br>PC program controls the filter selection.<br><br>2) When using multiple-receivers-on-a-single-Mercury mode (i.e., no jumper on GPIO pins 2-3 on Mercury and more than one receiver <br>requested by the PC) the Alex Tx and Rx filters are set to the "bypass" positions. This is so that the multiple receivers can be <br>operated on multiple bands simultaneously from the single antenna; the antenna should be a broad band antenna or multi-band antenna in this case, of course.<br><br>3) When using multiple Mercury board mode (i.e., GPIO pins 2-3 jumper in place on Mercury and more than one receiver requested by the PC) each Mercury board controls it's own Alex filter set (all Mercury boards are on the same frequency in this mode and all use identical <br>mode, filters, and other operating choice that are made on the (single) main PC display and the normal frequency break points for all <br>are as in 1) above unless "manual Alex control" is selected via the PC in which case the PC program controls the filter selection.<br></font></div><div><font face="Arial">A number of the PC programs will support multiple receivers and I will leave it to the individual authors to announce the availability of their code and configuration etc.</font></div><div><font face="Arial"></font> </div><div><font face="Arial">I'd like to thank Joe for his tenacity in hunting down a number of problems during the code merge and in particular for the code that only turns on additional receivers when selected.</font></div><div><font face="Arial"></font> </div><div><font face="Arial">Also thanks to the Beta testers for their invaluable input to the testing process.</font></div><div><font face="Arial"></font> </div><div><font face="Arial">As usual all feedback via the reflector please.</font></div><div><font face="Arial"></font> </div><div><font face="Arial">73 Phil...VK6APH</font></div><div><font face="Arial"></font> </div><div><font face="Arial"></font> </div></blockquote></div><div><div><br></div></div></body></html>